Method of reproducing electrical variations.



H. DE P. ARNOLD.

METHOD OF REPBODUOING ELECTRICAL VARIATIONS.

APPLICATION FILED JULY15.1012.

Patented Nov. 24, 1914.

ll IN zai 9 I I m" A /5 527 VW/nesses IIIIIIIII I //7 vemorx 628??? .m Ham/408k?! //7 0/4 A/fy.

HAROLD DE FOREST ARNOLD, OF IBELLEVILLE, NEW

ELECTRIC COMPANY, OF NEW YORK, N. Y., A

JERSEY, ASSIGNOR TO WESTERN CORPORATION OF ILLINOIS.

METHOD OF REPRODUCING ELECTRICAL VARIATIONS.

Specification of Letters Patent.

Patented Nov. 24, 1914.

Application filed July 15, 1912. Serial No. 709,444.

To all whom it may concern.-

Be it known that I, HAROLD DE FOREST ARNOLD, a citizen of the United States, residing at Belleville, in the county of Essex and State of New Jersey, have invented a certain new and useful Improvement in Methods of Reproducing Electrical Variations, of which the following is a full, clear, concise, and exact description.

This invention relates to the art of reproducing electric variations; its objects are to secure amplified reproduction of variations of current energy, reproduction without distortion, sensitiveness to minute currents, efficiency, reliability, and noiseless operation.

Among other uses the invention 15 applicable to telephony, for the purpose of obtaining in an outgoing ci'rcuit an amphfi cation of voice currents originating in an incoming circuit. 1

It is also applicable to telegraphy, and signaling systems generally where amplification is desirable in receiving, recording or reproducing impulses of electrical energy.

In carrying out the invention use 18 made of the principle of deflection by an electromagnet or other suitable means of an ionized stream which may be produced in any of a number of ways. The mercury arc has been found to be a suitable agent for the purpose. The current variations to be reproduced or reinforced may be 1mpressed on the coils of an electromagnet so situated that the variations of magnetism induced therein produce corresponding deflections of the ionized stream. The invention does not depend upon any effect in current flow which such deflection may have on the circuit of the ionized stream but involves a. novel method, which will now be explained, of detecting and utilizing the variations produced by the deflecting agent.

- The detecting means of this invention involves the use of an auxiliary circuit which is non-arcing in character and independent of the circuit for establishing the ionized stream, except that it traverses a portion of the vapor of the stream. This auxiliary circuit is maintained by means of an auxiliary cathode or pair of such cathodes immersed in the stream and connected to a source of electro-motive force which may be separate and distinct from the source producing the stream itself, the circuit being completed through an anode which may likewise be immersed in the stream. There is thus established in the vicinity of the auxiliary cathode or cathodes an electrical field, which causes in the auxiliary circuit a flow of current the intensity of which is directed dependent upon the distribution of ionization in the auxiliary cathode field.

The invention will be more fully understood by reference to the accompanying drawings wherein--11igure 1 shows a system of' circuits and apparatus by which the method hereinafter claimed may be carried out and Fig. 2 shows in elevation and cross section the apparatus of Fig. 1 separated from the circuits.

Referring to the drawings, the means for producing the ,ionized stream, which in this instance I haveshown as a mercury arc apparatus, comprises a main chamber 1 with a horizontal branch 2 and a. condensing chamber 3 4-, an anode 5 of carbon or other suitable material, and a starting mercury anode 6. Supported within the main chamber 1 are a pair of auxiliary cathodes 7, 8 which are shown semi-cylindrical in form and slidably separated from each other and from the walls of the chamber. Extending downwardly between the auxiliary cathodes is an auxiliary anode 9. The auxiliary cathodes and the auxiliary anode may be of platinum, or other suitable conducting material. Leading-in conductors preferably of platinum wire are provided for the several electrodes of the device.

As the means for deflecting the ionized stream, I have shown an electromagnet 10, the means of support of which is not shown. Such magnet comprises pair of coils 11, 12, surrounding inwardly extending pole pieces the outer ends of which are joined by a semi-circular yoke 18. The pole pieces present their faces to opposite sides of the main chamber 1 in the region of auxiliary cathodes 7, 8 so that the lines of force between the pole pieces are in a direction transverse to the direction of flow of the ionized stream in the chamber 1 and operate to deflect the stream in the direction of one auxiliary cathode or the other, according to the direction of the current in the magnet coils.

together with a mercury cathode I The system shown in Fig. 1 comprises five circuits-( 1) an incoming circuit 1 L including the coils 11, 12 of the electromagnet 10 and the secondary of an induction coil 15, the primary of which is in (2) a local circuit containing a source of current and a transmitting device such as the telephone transmitter 16; (3) an outgoing circuit 17 including a receiving device such as the telephone receiver 18 and the secondary winding 19 of a transformer 21; (4) an energizing circuit for the mercury are comprising a battery 22, impedance coil 23 and resistance coil 24, this circuit being connected, one terminal to the anode 5 and the other terminal to the cathode 4, and having a starting branch 25 connected, one terminal to the battery 22 and the other to the starting anode 6 and including a starting key 26; and finally (5) the auxiliary detecting circuit including a battery 27, one terminal of which is connected to the auxiliary anode 9 and the other branching through balanced primary windings 28 and 29 of the transformer 21 to the auxiliary cathodes 7 and 8 respectively.

The impedance coil 23 and resistance coil 24 provide a balance for the mercury arc circuits to maintain a steady flow of current therein which, when once established as by tipping the tube, closing the circuitat the starting key 26 over the path 22, 23, 24, 1, 2, 6, 2h, 26, 25, 22 and then releasing the key 26 is maintained automatically over the path 22, 28, 24, 1, 2, 1, 5, 22 which includes the ionized arc stream in the main chamber 1. This stream passes by and in contact with the auxiliary cathodes 7 and 8, filling the region between them, and rendering the auxiliary circuit conductive so that current flows from the battery 27 dividing through the primary windings 28 and 29 of the transformer 21 to the auxiliary cathodes 7 and 8, to and through the ionized vapor therebetween and by way of the auxiliary anode 9 back to the battery 27. It is noteworthy of this auxiliary circuit that it is non-arcing in character and that the potential difi'ereiice existing between the auxiliary electrodes is independent of, and in fact may be very much greater than, that existing between the electrodes of the arc stream. At the same time the current flow in the auxiliary circuit may be very much less than that in the arc circuit. For example, in one particular embodiment of the apparatus the potential difference existing between the auxiliary anode 9 and the auxiliary cathodes .7 and 8 was 100 volt whereas that between the anode 5 and cathode 4 of the arc was 30 volts. The current flow in this instance was .04 ampere in the auxiliary circuit and one ampere in the arc circuit. The primary coils 28, 29 of the transformer 21 are wound differentially in the auxiliary circuit, that is to say, in such a direction with respect to each other that the core thereof under normal conditions of the circuit is not magnetized. The normal current flows equally or approximately so in the two branches, this being due to the symmetrical arrangement of the auxiliary cathodes 7, 8 with respect to the ionized vapor in the space between them. When, however, the electromagnet 10 is energized by current received over the incoming circuit, 14, a magnetic field is produced which deflects the stream toward one electrode or the other. The efiect of this is a change in the distribution of ionization in the field or region adjacent the auxiliary cathodes and current will flow with increased strength through one primary winding of the transformer and with decreased strength through the other thereby inducing current in the secondary winding which is transmitted over the outgoing circuit 17 and recorded or made manifest in the receiving instrument 18. In this manner minute variations of current energy such as those transmitted over great distances by a telephone or signaling device and delivered to the iiistrument by the incoming circuit 14 are reproduced and amplified in the outgoing circuit 17. The extremely small mass of the ionized vapor Which is deflected by the electromagnet enables the reproduction of current variations to be accomplished without distortion. By reason of the non-arcing character of the detecting circuit the relaying of current variations is accomplished without disturbing or noisy currents in the outgoing circuit, this being of especial importance in telephone transmission sys tems.

I have illustrated and described two auxiliary cathodes and a branched circuit through balanced primary windings 28 and 29, for the reason that l have found that such arrangement roduces the best results. My fundamental invention would, however, be embodied in an arrangement in which only one auxiliary cathode and one primary winding are employed. Also the auxiliary anode 9 may be omitted and the battery 27 may be connected with the anode 5, without departing from the spirit of my inventicn. Moreover, while I prefer to use two magnet coils 11 and 12, one of them may be omitted, and indeed, the arc stream may be caused to be deflected by electro-static instead of electromagnetic means.

I claim:

' 1. The method of reproducin electrical variations which consists in esta lishing an ionized stream, maintaining a circuit including a transverse path within said stream, applying at a point within said path a variable deflecting force to said stream, and producing thereby current variations in the said circuit.

2. The method of reproducing electrical variations which consists in establishing an are, maintaining an auxiliary nonarcing circuit in a transverse path within said are, applying at a point Within said path a variable deflecting force to said arc, and producing thereby current variations in said auxillary circuit.

3. The method of reproducing electrical variations which consists in establishing an ionized arc stream, maintaining an auxiliary non-arcing circuit including a transverse path Within said stream, applying at a point within said path a variable deflecting force to said stream and producing thereby current variations in the said auxiliary circuit.

4. The method of reproducing electrical variations which consists in establishing an ionized stream, maintaining a balanced nonarcing circuit having two paths through a portion of the ionized vapor of said stream, deflecting said stream to and fro between said paths in accordance with current variations in an incoming circuit and transforming in an outgoing circuit the current variations thereby produced in the balanced circuit.

In Witness whereof, I hereunto subscribe my name this 13th day of July .A. D., 1912.

HAROLD DE FOREST ARNOLD.

Witnesses:

MURRAY V. CONATY, FRED DETHLOFF. 

